> Jean Leray (November 7, 1906–November 10, 1998) was confined to an officers’ prison camp (“Oflag”) in Austria for the whole of World War II. There he took up algebraic topology, and the result was a spectacular flowering of highly original ideas, ideas which have, through the usual metamorphism of history, shaped the course of mathematics in the sixty years since then.

It seems that solitude is generally conducive to creative activity for those that are somewhat positively oriented towards such activity.